Light pen



FIG. 1 is a perspective view of a light pen showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a bottom view thereof; and,

FIG. 8 is a second perspective view of the light pen, the ornaments depicted by means of broken lines being shown for illustrative purposes only and forming no part of the claimed design. 

The ornamental design for a light pen, as shown and described. 